Water Management and Precision Irrigation in Mediterranean Climate

The implementation of smart irrigation techniques that rely on plants as biosensors to assess water stress is necessary for sustainable water management. The aims of the thesis are first, to review the approaches for measuring and estimating plant-based variables, to describe their sensitivity in estimating water status for Mediterranean tree crops, and to highlight their strengths and limitations; second, to assess the potential of innovative techniques for the automated monitoring of water status of vines in Sardinia; and third, to evaluate the possibility of adopting new techniques to fight water scarcity in Lebanon. To achieve the first two aims, a study was conducted on Vitis vinifera L. Vermentino variety vines for 3 consecutive years (2019 – 2020 – 2021) in 3 sites in Sardinia (Italy). Sap flow was estimated using the T-max and the Heat Balance methods, and leaf turgor was estimated by leaf thickness. The automatic measurements were compared with the reference stress indicator midday stem water potential values. In addition, the evapotranspiration was calculated in 2021 using the energy balance equation according to the Surface renewal method. The results revealed a good fit between the variables and a promising potential in their implementation in an automated irrigation program albeit some technical, mathematical, and management limitations of the sensors. To accomplish the third aim, a survey was performed among irrigators of 4 governorates in Lebanon to assess the sociological, demographic, and education situations, as well as the current practices in irrigation. Their views regarding lack of water and their readiness to introduce new irrigation techniques were evaluated and the challenges were underlined. The possible strategies to improve irrigation management were highlighted with a vision to promote in other countries with similar environmental conditions and governmental status.